Commutator



A. C. HOPKNS.

COMMUTATOH.

APPLICATION mu) mmz. W9.

Patented Aug. 5, 1919.

snow x1301 ARTHUR C.HOF'KINS.

I the c? STATES PATENT OFFICE.

ARTHUR G. HOPKINS, F MINNEAPOLIS, MINNESOTA, ABSIGNOR '1 0 MID-WEST MANU- FACTURING COMPANY, OF MlNNE-APOLIS, MINNESOTA.

COMMUTATOB.

Specification of Letters Patent.

Patented Aug. 5, 1919.

Application Med Jenner-3 17, 1919. Serial No. 271,620.

To all whom it mam:

Be it known thatl, An'ruun C. Horxms, a citizen of the United States, resid ng at 1 Minneapolis, in the county of Hennepin and a State to in commutators for use more particularly in connection'with the Fordcngine,.and has 'for its objects to provide'an improved commutator which will be accurate in action, capable of convenient control and ready adjustment, and less subjected to wear as com pared with other commutators.

The invention has reference to the use of few and simple parts which, however, will be effective in operation for the purpose required. Other objects of the inventlon will be stated hereinafter. p

The inventiomeonsists of the. novel construction, combination and arrangement of parts as described herein and claimed, and

as illustrated in the accompanying drawing,

wherein Figure 1 is a view in longitudinal section of a commutator embodyin my invention, parts being broken away. Fig. 2 is a bottom 80 plan view of the casing. Fig, 3 is a plan view of the casing. Fig. 4 is a face view of a part of the wall of the engine to show an annular groove. Fi 5 is a side view of the movable, electrical contact-pin or plunger. Fig. 5 is a bottom plan view of a cap employed for the mounting of a cam upon the cam shaft. Fig. 7 is a plan view of a cam.

Referring now to the drawing for a more to particular description, the invention is illustrated in connection with'th'e wall 8 and combustion" c gine, said, wall being provided with an annu now 10 circumscribing and equidistant rom crture' 11 formed in said wall. At l is ihhimtedi casing preferably having the form of a. truncated cone, adapted to be seated in the groove 10. said casing being provided at its convergent end with a longitudinally apcitured, cylindrical insulating block 13 which, preferably rejects inwardly of said casing as clearly s own in Fig. 1, the casing also being provided at one of its sides with an apertured bracket 14 for receiving tional cam shaft 9 of an internal the end of a pull-rod 15. The cylindrical insulating block 13 is provided centrally with an upset projection a having-a con caved depression 1) formed therein twopen on its upper end.

As thus described the depression I) is dis posed in line with the cam-shaft 9, and in order that the casing 12 ma 'be maintained in the groove 10 and may be held therein without undue vibration I provide a flat spring 16, one of its ends being mounted. upon the conventional oil well 17 formed generally on the type of automobiles first mentioned, its opposite end being provided with a convexed projection 18 adapted to be seated in the depression 6 of the insulating hlock .'and it will be appreciated that the pressure upon all parts of the divergent end of the casin within the groove 10 will be uniform, this being an important feature for correct timing in the operation of the commutator, the resiliency of the spring 16 being adequate for the purpose mentioned and adapted to overcome the resistance of another part hereinafter to be mentioned.

Upon the shaft 9 is mounted. a cam 19 provided with a recess 20 for receiving the electrical contact-pin or plunger 21 and a spring 22, the latter normally causin a pressure of the pin against the inner ace of the cylindrical insulatin block 13, and mountedin the apertures 0 said block are electrical contact pins each being pro vided with an electrical conductor 24 con nected to the primary of a coil (not shown) the engine, the shaft 9 and plunger 21 operating asa part ofsthe electrical circuit, as usual. Numeral 25 indicates an apertured cap adapted to be threaded upon the cam fo use in combination with the nut 26 for sci uring the cam upon the shaft 9.

It will be understood that the cam shaft 9 is revolved by operation of the engine, and that the contact-pins 23 are disposed in the cycle ofmovement of the plunger 21 and ,thatelectric cineuits will be complete when Among some of the advantages to be de- In a eon'lmutator, the combination with rived by the present construction it may a cam shaft, of a wall having a hearing be stated that all of the functions required supporting one end of the ,cam shaft and for a commutator are discharged by a more having a groove made in one face of the 5 simple construction than usual and manuwall with a shoulder at the outer periphery facturo will be attended with a correspondof the groove and an inclined surface at the ingly less expense; since the plunger 21 is inner periphery of the groove, :1 frusto-conidisposed parallel with the axis of the shaft cal casing having its base seated in said S) the )ressure of the plunger against the groove and lying inside said shoulder,

0 face 0 theblock 9 and the ends of the memeans whereby the casing may be turned in tallic pins 23 will not be materially aflected said groove, an insulating block fastened in y centrifugal force. It will be understood the top of said casing, contact pins carried that the spring 16 is depended upon for by said block, a can turning with said cam holding the casing 12 upon its seat within shaft having a recess, a headed contact the groove 10 against the force of the spring plunger fitted loosely in said recess and an and operation of..friction of the plunger ranged to more over the first-named pins,

against the inner face of the insulating a spring in the recess beneath the headed l; block, and the fact that all of the force plunger, :1 projection on the block havirg a of the spring 16 is applied in line with the depression, and a flat spring having a con axis of the rotatable shaft 9, bymeans of vex knob resting in said depression and servthe concaved depression 6 and the convened ing to yieldin ly hold the casing in the projection 18 of the spring 16, tends to groove while alfinving the same to be turned. prevent vibration of the casing 12, and also In testimony whereof I have allixed my 5 permits an adjustment of more than usual signature in presence of two witnesses.

accuracy when the rod 1 5 is used, these ARTHUR (I. HOPKINS. being important features in operation. l'l'itnesses:

lVhat I claim as new and desire to secure ARTHUR H. S'l'UkGE-S,

by Letters Patent 1s:- Hmazu A. STURGES. 

